After looking for a more supportive seat for a Fortwo I hit a few problems, for insurance purposes the seats need to be steel backed as they are part of the smart's crash protection, this rules out nearly all aftermarket seats so something made by Smart was the obvious choice.

Roadster sport seats are a lovely upgrade as they are much more supportive without loosing any comfort.

The seats are held in the car with four Torx bolts (two front, two rear) and the bottom seat belt mount, undo these and the seats will just lift out.

The seats that I fitted were removed from a left hand drive Roadster so the cushions and covers needed to be removed and put onto my original Fortwo seat backs and runners as the belt holders and adjusters would be on the wrong side.

If the seats you have were for the correct hand drive then you just have to swap the runners.

You need to remove the bottom cushion to access the bolts by un-hooking it from the bottom of the frame and undoing the Torx bolts to release the runners, your Fortwo runner will need to be installed on the new seats.

Now all that is left is to reassemble the seat and bolt it back into the car. (ensuring that the seat belt is installed correctly)

All done, a very easy worthwhile modification.